Grinding machine



Patented Aug. 9, 1927.

UNITI-:D 'STATES PATENT OFFICE.

PAUL BRHL, or DUSSELDORF, GERMANY.

GRINDING MACHINE.

Application filled January 12, 1926, Serial No. 80,750, and in Germany January 14, 192.5.

by mechanical means the openations which:

are performed inthe hand grinding of such parts, and it is another object of my invention to provide a machine which will copy such hand operations by as simple means and as perfectly as possible. vSuch a main hand grinding, but the motions are ref n two sides. Vmay be adjusted by any -suitable means, not

lchine is equipped with non-rotary grinding plates of old type. y

In hand grinding, the operator displaces the parts on a stationary plate tovy and fro along scriblng circular curves so that the combined motion of the arts is along cycloids. While performin t is operation, the operator periodical y varies the osition of the part with regard to his handlby partly turning it about an axis at right angles to the grinding plate. X

In my improved machine, thisI combined motionis performed as follows:

The parts are placed in a cage .of old type in which they are rotated bodily about the axis-of the cage between two nonrotating but reciprocating grinding plates.

In this manner, all the motions are erformed and all the conditions are fulti led which have been found to be most suitable solved into -their components. While,'in hand grinding, one organ, the hand ofthe operator, imparts two motions, a straight `and a circular one, these two motions are performed in-my machine by two organs. the cage which performs the circular mo- 'tion and the rinding plates which perform the vstraight-line motion. In both cases, however, the result is the same' for in the machinethe circular motion of the parts 'in the rotary cage is combined with the` straight-line motion of the grinding plates into a cycloid, as in hand grinding, the partial turning about their axis at right angles to the grinding plate being effected by their motion in circular curves aboutthe laxis of the cage between the plates, due to the various ve they are engaged by said plates.

By providing two grinding plates instead of a single plate as in hand grinding, obvisubstantially straight lines whilel deocities of the points at whichl the same time, the possibility is provided of reciprocating the plates in lop v4oslte directions, this involving the good eature thatA they are permanently -maintained fiat -and it is not necessary to. re-grind them periodically. In my machine, all parts in a cage are ground exactly Eto the same dimensions and it is not necessary, as in the old machines, to vary the relative position of the parts in the cage periodically.

The Grinding plates may be of material ig properties, for instance,cast iron. In this latter case, a mixture of oil and emery is supplied to the grinding plates.

In the drawings, a machine embodying my v invention is illustrated by way of'example. Figs. 1, 2 and 3 are anelevation, an end view from the left in Fig. 1, and a plan view,

in section along the line III-III of Fig. 2, showing a machine embodying the principles of my invention.

Referring now to the drawings, 1 is the frame of the machine in which a driving shaft 2 equipped with a step pulley 2 and a clutch 2' is carried. 6 is a bevel gearing whichimparts rotation to a vertical shaft 6 on which the cage 5 is secured concentrically, 5 designating recesses in said cage lfor the parts to be tooled, for instance, gauge blocks, rings for ball bearings, balls or rollers 16. 3 is the upper and 4 is the lower grinding plate which engage the parts in the cage on The distance apart of said'plates shown, and if desired, they may be held onto the parts by springs, not shown.

Any suitable means-may be provided for reciprocating said plates. stance links 7, 17' are pivotally connected with the plate 3 and the slide 14 of the plate 4 at one end, and to bell-crank levers 8, 8

pivotally carried in the frame 1, at the other.

any desired relative motion may be imparted to the plates 3 and 4. Displacing the plates in opposite directions is most favourable as ously the output will be increased and, at varied most effectively, providing 'for reliable lgrindingv or any other material-of non-grind- In the present inin this case the points of contact Jill be' action of the grinding plates on the parts .and for reliable maintaining of the flat condition of nthe plates themselves. Such motion of the grinding plates is obtained wheny the pins are secured at opposite ends of their respective slots, as shown. in Fig. l, the plates 3 and 4 will move in opposite directions. If the pins are at the same ends of their slots, the plates will move in unison, and, if the pins are placed c0-axially with the shaft, the plates will not move at'all. Obviously, various intermediate stages may be provided by suitable adjustment of the pins.

The operation of my machine will be understood from the foregoing description. The parts are bodily moved round and round between the reciprocating grinding plates until the operation is completed, and, as mentioned, it is not necessary to exchange the relatiye position of the parts in the cage in order to. avoid irregularities yin size. The continuous reciprocation of the grinding plates relativel to the parts, this reciprocation being suc that the parts are ground all over their surfaces, has the further advantage that the faces will remain Hat without special operations for this purpose, viz, regrinding,

I claim: f 1..Grinding machine comprising a pair of grinding plates, means for reciprocating said grinding plates, and a rotary cage betweenl said plates in which the parts to be ground are inserted.

2. Grinding machine comprising a pair of grindin plates, means for alternately reciprocating said plates, and a rotary cage between said plates in which the parts to be ground are inserted.

` 3. Grinding machine comprising a pair of grinding plates, means for reciprocating said grinding plates, means for varying the stroke of said grinding plates, and a rotary cage between said-plates in which the parts to be ground are inserted.

In testimony whereof the foregoing speciication is signed.

- PAUL BRHL. 

